Outlook and Charter/Spectrum can't send or receive email.

[RetiredCHE]

I am running 32 bit OL 2013 on 64 bit Win 10 Pro fully upgraded. My email provider is charter.net for many years, long before they converted to IMAP and became part of Spectrum. At some point an issue developed whereby I could not send email except when connected to my secured home network. I could receive email via any internet connection, but only send when at home.
I found a page on Spectrum’s website, since Charter is now Spectrum, with “updated” recommended settings for the server names, port #’s, etc, which I changed to using the Outlook account “change settings” feature. Now I can’t send or receive email, even when at home. I tried going back to the previous (default) settings, but it still doesn’t work. I have tried the Outlook settings repair feature, but nothing has worked. I have done several chat sessions with Spectrum support, but they just keep telling me to use their recommended settings, and that I should call Microsoft if that doesn’t work.
Outlook works; the program still comes up just fine, and I can read the email that was already received before this issue. I can also send an receive using Spectrum's webmail application. I don’t know where to go from here. Can anyone point me in a direction to try, please?